I have spent a little time on Route 66 and I can't imagine needing a GPS for anything. I guess if it points out some sites to see that sort of thing but damn, it's all over the net. You can do a little studying and you will have TOO MUCH stuff to do. I know I can give you a bunch, oh my God I love those road trips. The "Historical Route 66" above Kingsman is cool too.
Brian